Big challenge returns to Hawaiian Island waters
On the morning of November 21st, 2012, a group of specialists arrive at Coast Guard Station Maui to face an annual challenge here in the Hawaiian Islands. Humpback whale season is beginning, and this assembly of scientists and first responders prepare to combine their skills, in an effort to aid marine mammals that have been entangled in fishing gear or suffered from vessel collisions.
Humpback whales complete their annual migration to the most isolated archipelago in the world each year, usually between November and April. During these months they remain in the waters surrounding Hawaii to breed, give birth and nurse their young. While transiting to or living in the Hawaiian Islands, it is common to receive reports of injured humpback whales, or animals entangled in various kinds of large fishing gear like nets and lines.
The National Oceanic Atmospheric Administration’s Hawaiian Islands Humpback Whale National Marine Sanctuary Program leads the effort to respond to entangled or injured humpback whales. The Coast Guard and the Hawaii Department of Land and Natural Resources work together with NOAA to respond to reports.
Entanglement and ship strikes are some of the primary threats to large whales, like the humpback. Since 2002, combined response efforts have freed 16 whales from life-threatening entanglements and more than a mile of gear has been removed from the animals.
“Trying to cut a 40-ton, 45-foot animal free of entangling gear is no easy task. It is quite dangerous for rescuers and the entangled animals alike,” said Edward Lyman, large whale entanglement response coordinator for the Hawaiian Islands Humpback Whale Marine Sanctuary. “It is an activity that falls under federal and state permits and requires authorization. It is a task best left to those with experience, equipment and training.”
Lyman explained that there are likely many reasons that entanglements happen. In some cases the animals stumble into the gear, having not detected it because it is cryptic like a gill net, or they are distracted during other activity. Whales sometimes target the gear. For example they may be trying to get the fish from nets or use them as a scratching post to remove parasites. In Hawaii, Lyman suspects that the juveniles are often entangled while playing with nets and debris.
The sanctuary leads disentanglement efforts, but doesn’t have the resources to do it alone. Crew members at Coast Guard Station Maui, located at Maalaea Harbor on Maui’s South Shore, usually work in support of the Coast Guard’s search and rescue or law enforcement missions. During humpback whale season, station personnel assist NOAA in order to maximize coverage of the broad area of response.
“It’s great to challenge our coxswain and crewmember’s search and rescue skillset with something different,” said Chief Petty Officer Erin Stapleton, officer in charge at Station Maui. “This unique situation allows them to branch out into the Coast Guard’s living marine resources mission, which is something our crews are very likely to be involved with as they progress in their Coast Guard careers.”
The training consists of classroom presentations followed by hands-on practice. During the hands-on session, one vessel drags a line in the water, simulating a whale dragging a net or debris. Crewmembers on a second vessel make attempts to toss a grappling hook over the line to snare it. The grappling hook has a line, buoy and global positioning system transmitter attached to it, allowing the simulated ‘entangled whale’ to be tracked.
“Freeing an entangled whale of gear actually involves an old whaling technique called kegging. Whalers in the 1800s would throw a harpoon not to kill the animals, but to attach to it. They would get a Nantucket sleighride in their wooden skiffs,” said Lyman. “If the whale dove they would attach a wooden barrel or keg to slow the animal down and keep it near the surface. Once staying at the surface, a behavior called ‘logging’, they would drive a lance into its vitals to bleed the animal out.”
He explained that the process of freeing an animal is similar in that we need to get a hold of it. Instead of a harpoon a grappling hook is used. The grappling hook targets the net, line or debris, not the animal. The procedure uses inflatable boats instead of wooden skiffs, buoys instead of kegs and hooked knives to free the animal instead of lances to kill it. The tag buoy acts as the ‘keg’ and if needed tracks the animal over time with a built in global positioning system transmitter.
Lyman noted that humpback whales are not typically in immediate danger, sometimes being large enough to carry the gear over long distances and for considerable time. They still may eventually fall victim to the entanglement from the physical trauma of gear cutting into flesh, restricted mobility affecting the ability to feed or associated impacts like infection or ship strikes. Some removed gear picked up was from the Bering Sea, Alaska, more than 2,875 miles away.
“In fact, finding out what the gear is, where it came from and how the animal may have become entangled is the ultimate goal of this collaborative effort,” said Lyman. “Freeing an animal from an entanglement that may eventually kill it is indeed important, but gaining information towards prevention is ultimately how we will reduce the threat to these animals.”
While not everyone is authorized or able to free an entangled large whale, the on-water community of tour boat operators, whale researchers, fishermen and others, are instrumental towards the effort. It is this group of mariners that help find the animals, report, provide initial assessment and documentation and monitor until a rescue team can arrive.
Mariners are required to maintain a distance of 100 yards, and reminded not to follow directly behind the animal to avoid trailing gear becoming entangled in prop or jet drives. If sited, monitoring of the animals from a safe and legal distance is critical to the success of a response. An entangled whale is a very large needle in an even larger haystack, and can be difficult or impossible to locate again. To report a marine mammal in distress, call the NOAA Fisheries 24-7 Marine Mammal Hotline at (888) 256-9840 or contact the Coast Guard on VHF Ch 16.
Source: USCG media release